Aperture: Reformat activity_main.xml

Change-Id: If4ee430c152813767993fa01d1372ac9fc0e16a1
diff --git a/app/src/main/res/layout/activity_main.xml b/app/src/main/res/layout/activity_main.xml
index ef25774..d7f018b 100644
--- a/app/src/main/res/layout/activity_main.xml
+++ b/app/src/main/res/layout/activity_main.xml
@@ -231,9 +231,9 @@
 
         <ImageButton
             android:id="@+id/shutterButton"
-            android:background="@null"
             android:layout_width="75dp"
             android:layout_height="75dp"
+            android:background="@null"
             android:contentDescription="@string/shutter_button_description"
             android:src="@drawable/avd_photo_capture"
             app:layout_constraintBottom_toBottomOf="parent"